Mobile crane



March 28, 1950 w, TAYLOR MOBILE CRANE Filed July 16, 1946 MINI InventorPatented Mar. 28 1956 OFF'I CE.

MOBILE William Taylor Salford, England? Application July 16, 1946,Serial No. 683,856 In Great Britain September 1, 1945 3 Claims.

This invention relates to improvements in mobile cranes such as arecarried by self-propelled motor vehicles.

According to the invention the main jib of a crane is fulcrumed at itsrear end on a frame carried by the chassis or other part of the vehicle,and supported at a point intermediate its ends on an auxiliary jib alsofulcrumed on the frame a ram operating in an hydraulic cylinder raisingor lowering the auxiliary jib which raises or lowers the main jib.

The invention is illustrated diagrammatically in and will be describedwith reference to the accompanying drawings in which:

Fig. 1 is a side elevation showing the jib in its lowest position;

Fig. 2 is a side elevation showing the jib in its highest position;

Fig. 3 shows a part side elevation of a modification of the mounting ofthe auxiliary jib on the main jib;

Fig. 4 is a section on line 44 Fig. 3 enlarged.

The main jib A is fulcrumed at its rear end on a frame B carried by thechassis at the rear end of the vehicle. The lower end of an auxiliaryjib A is pivoted on the frame B adjacent to the chassis, the fulcrumedend of the two jibs A 3 being substantially separated with the upper endof the auxiliary jib A connected to the main jib intermediate its endsby rollers a engaging runways or guides 11 in the main jib A In themodification shown in Figs. 3 and 4 the main jib A is provided with aninclined surface a of channel shape on its underside the flanges a ofwhich are engaged by flanged rollers a mounted on a shaft a carried bythe auxiliary jib A to enable a greater lift to be obtainedoralternatively the same lift with less movement of the auxiliary jibwhilst still allowing the main jib to be brought down. to the positionshown in Fig. 1.

The hook end of the main jib A may be formed with a series of slots 9 toenable a hook G to be suspended at varying distances from the end.

The auxiliary jib A is connected at a point chassis; a frame mounted onsaid chassis; a main jib pivoted at its rear end to said frame; anauxiliary jib pivoted to said frame at a point spaced from and below thepivoting point of said main jib; rollers on the free end of saidauxiliary jib; flanges forming an inclined surface on the lower face ofsaid main jib; arranged so as to be engaged by said rollers on saidauxiliary jib; a hydraulic cylinder member; a motor member operating insaid hydraulic cylinder member; first pivoting means pivoting one ofsaid members to said chassis; and second pivoting means pivoting theother of said members to said auxiliary jib whereby movement of saidmotor member 'within said hydraulic cylinder member will raise or lowersaid auxiliary jib and thereby raise or lower said main jib too, saidinclined surface giving increased lift to said main jib over thatimparted by said motor.

2. A mobile crane carried by a movable vehicle comprising in combinationa main jib; first pivoting means pivoting said main jib at its rear endto said movable vehicle; an auxiliary jib; second pivoting meanspivoting said auxiliary jib at one end to said movable vehicle at apoint spaced from and below said first pivoting means in such a mannerthat the other end of said auxiliary jib engages the lower face of saidmain jib at a point substantially spaced from said first pivoting means;a hydraulic cylinder member; a piston member operating in said hydrauliccylinder member; third pivoting means pivoting one of said members tosaid movable vehicle at a point spaced from said first and said secondpivoting means; and fourth pivoting means pivoting the other of saidmembers to said auxiliary jib at a point spaced from said secondpivoting means whereby movement of said piston member within saidhydraulic cylinder member will turn said auxiliary jib about said secondpivoting means, which turning movement of said auxiliary jib in turnwill result in turning of said main jib about said first pivoting means.

3. A mobile crane carried by a movable vehicle comprising in combinationa main jib; first pivoting means pivoting said main jib at its rear endto said movable vehicle; an auxiliary jib; pivoted at its rear end tosaid vehicle at a point spaced from and below said first pivoting means;roller means freely rotatably mounted on the other end of said auxiliaryjib; means forming a supporting surface on the lower face of said mainjib arranged at a point spaced substantially from said first pivotingmeans in such a manner as to be engaged by said roller means; ahydraulic cylinder member; a piston member operating in said hydrauliccylinder member; third pivoting means pivoting one of said members tosaid movable vehicle at a point spaced from said first and said secondpivoting means; and fourth pivoting means pivoting the other of saidmembers to said auxiliary jib at a point spaced from said secondpivoting means whereby movement of said piston member within saidhydraulic cylinder member will turn said auxiliary jib about said secondpivoting means, which turning movement of said auxiliary jib in turnwill result in turning of said main jib about said first pivoting means.

WILLIAM TAYLOR. 15

4 REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 363,066 Harris May 1'7, 1887503,362 Biehn Aug. 15, 1893 676,504 Kassel June 18, 1901 10 2,019,938Stephens Nov. 5, 1935 2,342,942 Johnston Feb. 29, 1944 2,395,622Galbreath Feb. 26, 1946

